diff --git a/skimage/_shared/testing.py b/skimage/_shared/testing.py
index d012b8b6..0f556acf 100644
--- a/skimage/_shared/testing.py
+++ b/skimage/_shared/testing.py
@@ -186,7 +186,7 @@ def setup_test():
     Set a random seed
     """
     warnings.simplefilter('default')
-    from scipy import signal, ndimage, special, optimize, linalg, sparse
+    from scipy import signal, ndimage, special, optimize, linalg
     from scipy.io import loadmat
     from skimage import viewer, filter
     np.random.seed(0)
diff --git a/skimage/segmentation/tests/test_random_walker.py b/skimage/segmentation/tests/test_random_walker.py
index 5877a817..d925592c 100644
--- a/skimage/segmentation/tests/test_random_walker.py
+++ b/skimage/segmentation/tests/test_random_walker.py
@@ -99,7 +99,7 @@ def test_2d_cg_mg():
     lx = 70
     ly = 100
     data, labels = make_2d_syntheticdata(lx, ly)
-    with expected_warnings(PYAMG_EXPECTED_WARNING):
+    with expected_warnings('%s|\A\Z' % PYAMG_EXPECTED_WARNING):
         labels_cg_mg = random_walker(data, labels, beta=90, mode='cg_mg')
     assert (labels_cg_mg[25:45, 40:60] == 2).all()
     assert data.shape == labels.shape